TW543060B - SMA actuator with improved temperature control - Google Patents

Abstract

A SMA actuator having rigid members and SMA wires, in which improved temperature control of the SMA wires of the actuator is provided by a heat sink, which may be the rigid members themselves, in close proximity to at least a central portion of the wires. Optionally, the heat sink is sized and placed such that the end portions of the wires where they are attached to the rigid members are not in close proximity to the heat sink. Where the heat sink is external, it optionally has a cooling element that acts passively as a heat sink during the heating cycle of the actuator and that acts as an active cooling element during the cooling cycle of the actuator. An SMA actuator, having a desired contraction limit and a power supply circuit, has a switch in the power supply circuit that is normally closed when the actuator is contracted to less than the desired contraction limit and is opened by the actuator reaching the desired contraction limit. This improved temperature control provides greater cooling of the SMA wires for a faster response and an extended working life of the actuator.

Description

A7 543060 ________B7 _ V. Description of the invention (I) Background of the invention (Please read the notes on the back before filling out this page) The present invention relates to shape memory alloy (S ΜA) actuators. Specifically, the present invention relates to SMA actuators, and in particular, to miniaturizable S MA actuators with improved temperature control for faster response and longer operating life. Explanation of related prior art In the 1950s, a material with a shape memory effect was discovered. See, for example, "Shape Memory Materials", published by K. Otsuka and CM. Wayman, Cambridge University Press, Cambridge, UK, ISBN 0-521-44487X. These materials--lines · The material has a thermoelastic martensitic transformation, that is, it is bendable below a certain transformation temperature, because the material is in its martensitic phase and can be easily deformed. When its temperature rises above this transformation At temperature, the material reverts to its austenite phase and its previous shape and generates considerable force at this time. An example of this material is titanium nickel (T i N i) at about 50:50 atomic percent. Alloys that can optionally contain small amounts of other metals to provide improved stability or change the martensite-austenite transition temperature; and these can be formulated and processed to exhibit shape memory effects. Other such alloy systems include copper / aluminum / Nickel and copper / aluminum / zinc alloys, sometimes called /? Copper. Such alloys are often called shape memory alloys (SMA) and can be in the form of metal wires with diameters as small as 37 microns to 1 mm or larger And purchased from several sources, see for example California 92715 I rv i ne County Dyna 1 1 〇y shares 4 This paper size applies Chinese National Standard (CNS) A4 specifications (210 x 297 mm) 543060 A7 ------ B7___ V. Description of the invention (> /) Co., Ltd.'s technical information manual "Technical Characteristics of Flexinol Actuator Wires" o SMA metal wire is a shape memory alloy metal wire, which is processed so that it is in the martensite phase It can easily be stretched along its long axis, thereby rearranging its atomic lattice structure. Once stretched, it is maintained in this manner until heated above its austenite transition temperature, at which point the lattice structure returns to its original ( (Memory) austenite structure. This recovery not only restores the metal wire to its original length, but also generates a considerable amount of force, usually the pressure on the cross-sectional area is in the order of 50 kgf / mm2, according to the alloy and its treatment Depending on the method. Because considerable force can be obtained per unit cross-sectional area, SMA metal wires are usually made in small diameters. For example, a 100 micron diameter metal wire can transmit about 250 grams of force. To obtain greater power, thicker metal wires or multiple metal wires are required. Although SMA has been known since 1951, commercial actuators are applied due to the inherent limitations of certain physical processes that produce shape memory properties. Limited. Lack of commerciality due to a combination of the following factors: (1) The limited displacement titanium nickel S SMA wire can shrink up to 8% of its length during the transformation of thermoelastic martensite to austenite. However, the degree of extension here It can only maintain a few cycles before it fails. For reasonable cycle life, the maximum extension is in the range of 3%-5%. For example, for an actuator with a reasonable cycle life, an SMA wire exceeding 25 cm is required to produce a movement of 1 cm. ___ ^ __ This paper size applies to Chinese National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page)

A7 543060 ___B7___ V. Description of the invention (^;) (2) Minimum bending radius An obvious solution for loading very long s ΜA into a small space is to use some kind of pulley system. Unfortunately, SMA wires can be harmed when they bypass sharp bends. The bending radius of SMA wire should not be less than 50 times the diameter of the wire. For example, a ' 250 micron diameter metal wire system has a recommended minimum bending radius of about 1.25 cm ' for high cycle life. It should be noted that the term "minimum bending radius" used here refers to the minimum radius of the SM wire that can bend and still repeat the austenite-martensite cycle without harm. The addition of a large number of small pulleys makes the system It is more complicated, which firstly eliminates the incentive to use S MEMS. In addition, the minimum bending radius requirement creates a lower limit on the size of the actuator. (3) Cycle time SMA wires are usually heated resistively by current. . Then the wire needs to be cooled below its Ms temperature before being retracted back to its starting position. If the cooling is done by convection of still air, it may take a lot of time before the actuator can be used again. Above The optimal cycle time of a 250 micron metal wire in free air is about 5 seconds or longer. Therefore, for example, a SMA-powered walking insect [JM · Conrad and JW · Mills by Los Alamitos, Likou, USA "Stiquito: Advanced Experiment with a Simple and Inexpensive Robot" by IEEE Computer Society Press, County , ISBN 0-8186-740S_3] can only reach a walking speed of 3-10 cm / min. Because the cooling rate is determined by the ratio of the surface area of the wire to its volume, the change in the diameter of the wire can affect the cycle time, More than 6 paper sizes are applicable to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page)

A7 543060 ______B7_ V. Description of the Invention i: f) Small metal wires have shorter cycle times. The problem of cycle time is even more serious when the SMA actuator is used in a repeating switching cycle such as Stiquito or similar toys or in another environment where the actuator canned cycle. Subsequently, air and any other components surrounding the SMA component may be heated above the external ambient temperature, causing the ability of the SMA component to dissipate and cool to a martensitic state. The working life (cycle number) may also be adversely affected by the inability to control the cooling. The rapid heating to achieve complete shrinkage usually may cause the S MA metal wire to significantly exceed the A f temperature, especially in the middle part of the metal wire; And such repeated large temperature deviations will lead to fatigue and loss of working life of the metal wires. To overcome these limitations, designers using SMA actuators often use long straight metal wires or coils. For example, refer to M. Hashimoto, M. Takeda, Η · Sagawa, I. Chiba, and K. Sato, published in 1985 and Mw / c Office Price, Volume 2, Issue 1, Issue 3 -25-page "Application of Shape Memory Alloy to Robotic Actuators"; published by K. Kuribayashi in / 1986, Vol. 4, No. 4, Issue 4 4 7 — 5 “A New Actuator of a Joint Mechanism using TiNi Alloy Wire” on page 8; published by K. Ikuta on May 5, 1990 "Micro / Miniature Shape Memory Alloy Actuator" (Vol. 3, pages 2151-2161); and K. Ikuta, M, Tsukamoto, and S. Hirose Order 7 This paper size applies to Chinese National Standard (CNS) A4 (210 χ 297 mm) (Please read the precautions on the back before filling this page)

A7 543060 __B7 _ V. Description of the invention (() (Please read the notes on the back before filling in this page) 1 QQ 8 years published in Proc · IEEE Int. Conf · on Robotics and ⑽ page 427 — 430 "Using resistance Feedback Shape Memory Alloy Servo Actuator with Electrical Resistance Feedback and Application for Active Endoscope ". In many applications, especially when miniaturization is desired, long straight metal is used The line is obviously impractical. Although the line can greatly increase the stroke of the transmission, it is large and significantly reduces the available force (the force is proportional to the sine of the pitch angle, which is the overall coil axis and the coil The angle between the stern axes may be as small as a few degrees); and, to compensate for the decrease in force, a thicker metal wire is required, which will reduce the responsiveness of the resulting actuator, making it unsuitable for many Application. Generally, other mechanisms used to mechanically enlarge the displacement that can be obtained have encountered the same limitation of available force, which again leads to The requirements of thick metal wires and the problems associated with cycle time, such as those revealed in D. Grant and V. Hayward, published in 1997 / Wu Cong Li Xu Xian Vol. 17 No. 3 Issue 8 0-8 8 "Variable Control Structure of Shape Memory Alloy"

Actuators) "and U.S. Patent No. 4,806,815. The common method of heating an S MA actuator to its transition temperature is pulse width modulation (PWM). In this method, a fixed The voltage is used as a percentage of the preset period. When the percentage of the ON time to the OFF time in a single period is changed (called the duty cycle), the total amount of power delivered to the S MA can be controlled. It is easy to implement in digital systems, so The method is very general. 8 This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) A7 543060 _B7 5. Explanation of the invention (^) times, it only needs a single transistor to drive the actuator, no digital analog Conversion and matching amplifiers. PWM control is particularly attractive because many commercial microcontrollers include built-in hardware for generating PWM signals, which reduces the computational load on the controller. In addition, PWM outputs are often used for sound effects Chips (such as those used in "speaking" greeting cards and similar items) as inexpensive digital-to-analog conversion mechanisms, making these low-cost chips suitable for use as control of S MEMS actuators of the present invention. In some applications, full PWM control may not be required, and inexpensive timing chips may be used to generate the required digital signals. In addition, because current limiting resistors are not required to avoid overheating the SMA component, when a temperature signal is available The PWM control reduces the average current draw. In addition, because the current flow of the SMA metal wire tends to be concentrated on the surface of the metal wire (same for all solid conductors), there is a danger of "hot spots" and uneven heat distribution, which reduces metal The life of the wire. The regular transmission of the excitation voltage causes the heat conduction of the S MA wire to form a more uniform heat distribution. In addition, in the conventional DC control system, the SMA current determined by the current-limiting resistance is actually constant and quite low In order to avoid overheating of the SMA device after it has fully contracted, in the PWM or pulse method with resistance feedback, a high duty cycle can be used when starting to heat the SMA device to form a fast initial movement. When the S MA element reaches the desired position, only sufficient power is supplied to maintain the S MA element in the desired state, thereby reducing the working cycle In SMA, the transition from the martensite (low temperature) phase to the austenite (high temperature) phase does not occur suddenly at a specific temperature, but is in a temperature range __ 9 (Please read the precautions on the back before filling out this (Page). This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) A7 543060 ____B7___ V. Description of the invention (7) is carried out gradually. Figure 1 shows the displacement of a typical SM A metal wire And the relationship between temperature, the SMA wire is placed under tensile stress and stretched in its martensitic state, shrinks and transforms into an austenite state when heated, and re-stretches and cools back under tensile stress when cooled. Martensitic state. Figure 1 shows the austenite starting As and the austenite ending A f temperatures, and the martensite starting Ms and the martensite ending M f temperatures, respectively. In the temperature range indicated by ΔT, the alloy consists of a mixture of austenite and martensite. It can be seen from the figure that when the S M A is heated, the length does not change basically when it is less than six s, and the length on the substrate does not change further when it is higher than A f. Similarly, when cooling, the length does not change substantially above Ms and does not change further below the basic length; however, the length-temperature curve usually has a large amount of hysteresis. In addition, the maximum contraction of the SMA metal wire requires heating the metal wire to a temperature exceeding Af, and the maximum heavy extension requires cooling to a temperature below Ms. This means that in practice, such a metal wire usually needs to be operated in a range from absolutely below M s to absolutely above A f to obtain maximum contraction / heavy elongation. The disclosures of all documents cited in this section and in other sections of this application are incorporated herein by reference. There will be a need to develop S MEMS actuators with improved temperature control for faster response (lower cycle time) and extended operating life (higher number of cycles can be obtained). Invention: In the first idea, the present invention provides a paper that includes a strong component and _ 10 paper size applicable to China National Standard (CNS) A4 (21 × 297 mm) (Please read the precautions on the back before (Fill in this page)

543060 A7 ___ B7__ 5. Description of the invention (/) (Please read the precautions on the back before filling out this page). Wire S Μ A metal wire S Μ A actuator, of which § μ A metal wire Improved temperature control is provided by a heat sink that is in close proximity to at least the middle portion of the wire. When the solid member is highly thermally conductive (for example, when it is made of metal), the heat sink may contain the solid member itself so that the metal wire should be close to the solid member at least in the middle of the metal wire; or the heat sink The actuator may be external to the actuator. This actuator is usually a "stacked plate" actuator. In the second concept, the heat sink is sized and positioned such that the end portion of the metal wire connected to the solid member is not in close proximity to the heat sink. In a third conception, the present invention is a shape memory alloy actuator having an external heat sink that includes passively acting as a heat sink during the heating cycle of the actuator and a cooling cycle of the actuator. As the cooling element of the active cooling element. In a fourth concept, the present invention provides an S MEMS actuator having a desired contraction limit and a power supply circuit. The power supply circuit includes a switch that shrinks the actuator to less than desired. The contraction limit is normally closed and the actuator is opened when the desired contraction limit is reached. The improved temperature control of these actuators can provide better cooling of the S SMA wire for faster response (shorter cycle times) of the actuator, as it avoids excessive heating of the wire and therefore metal fatigue Therefore, it also provides a longer working life for the actuator. Brief Description of the Drawings Figure 1 shows a plot of length vs. temperature for a typical SMA element. 11 This paper size applies to China National Standard (CNS) A4 specification (210 X 297 mm) 543060 A7 ___B7__ V. Description of the invention (^) Figure 2 shows a perspective view of a stacked flat SMA actuator, which shows the SMA metal wire and Location of sturdy components. Fig. 3 shows a sturdy element for a stacked flat SMA actuator showing an embodiment of the first concept of the present invention. Fig. 4 is a perspective view of an embodiment of an S MA actuator using the sturdy element of Fig. 3; Fig. 5 A is a side view showing the actuator of Fig. 4 in its extended structure. Fig. 5 B is a view showing the actuator of Fig. 5 A in its retracted structure. Fig. 6 shows a sturdy element of an SMA actuator of the present invention, which shows another embodiment of the first concept of the present invention. Fig. 7 shows another sturdy element for the SMA actuator of the present invention, which shows the first and second embodiments of the present invention. Fig. 8A shows another sturdy element for the SMA actuator of the present invention, which shows another embodiment of the first and second ideas of the present invention. Fig. 8B shows another sturdy element for the SMA actuator of the present invention, which shows another embodiment of the first and second ideas of the present invention. Fig. 9 is a view showing a solid component of another S MA actuator of the present invention, an SMA metal wire, and a base, showing one embodiment of the first and second concepts of the present invention. FIG. 10 is a side view showing an assembled actuator using the component / wire assembly of FIG. 9. FIG. 12 ^ 1 scale is applicable to China National Standard (CNS) A4 specification (210 X 297 mm) ~ " (Please read the precautions on the back before filling this page). · Line 543060 A7 B7 V. Description of Invention (/ P) FIG. 11 schematically shows the concept of the present invention, wherein the actuator has a switch to cut off the power supply to the actuator when the actuator reaches a desired contraction limit. Component symbol description 2 0 · 2 1 · 2 1 A 2 2 · 2 2 A 2 2 B 2 3 · 2 3 B 2 11 2 12 2 2 3 2 3 1 3 0 · 3 1 · 3 2 · 3 2 A 3 2 B 3 3 ·

3 3 A Stacked plate actuator sturdy conductive plate connection point sturdy conductive plate connection point connection point sturdy conductive plate connection point external connection point S ΜA metal wire S ΜA metal wire external connection point actuator shaft end external connection point metal wire Connection point end external connection point 13 (Please read the precautions on the back before filling this page)

This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 543060 A7 _Β7 V. Description of the invention (/ /) 3 3 B ..... Metal wire connection point 4〇 ... Actuator (Please read the precautions on the back before filling out this page) 4 1 ... stacking plate 4 1 A ..... connection point 4 2 ... stacking plate 4 3. .... stacking plate 4 4 ... stacking plate 4 5 ... stacking plate 4 6 ... stacking plate 4 6 B ..... connection point 4 7 .. .... shell 4 11 ..... extension 4 12 ..... S Μ A metal wire 4 2 3 ..... S Μ A metal wire 4 3 4 ..... S Μ A metal wire 4 4 5 ..... S Μ A metal wire 4 5 6 ..... S Μ A metal wire 6 1 ... S Μ A metal wire 6 2 ..... .Strong member 6 2 A ..... end 6 2 B ..... end 6 3 ... straight edge 7 1 ... S Μ A metal wire 7 2 .... .. sturdy member 14 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) A7 543060 _B7 V. Description of the invention (/ l) 7 3 ··· • Straight edge 7 4 ···· Concave Hole 7 5 ···· Bottom edge 8 1 ··· • S ΜA metal wire 8 2 ···· Sturdy member 8 3 ···· Straight edge 8 4 ··· • Recess 8 8 ···· Bottom edge 8 11 ·· • S Μ A metal wire 8 12 ··· Sturdy member 8 13 ··· Edge 8 14 ··· Recess 9 9 ·· • Component 9 2 ··· • Base 9 2 A · · • Base plate 9 2B · · · Plug 9 2 C · · · Plug 9 11 · · • Flat 9 11A · • Clip 9 9C · • Connection point 9 1 1 D · • Connection clip 9 12 ·· • Flat plate 9 12A · • Clip connection point 9 1 2 B · • • Clip connection point 15 (Please read the precautions on the back before filling this page) This paper size is applicable to China Standard (CNS) A4 specification (210 X 297 mm) 543060 A7 B7 V. Invention description 9 13 · 9 1 3 A 9 1 3 B 9 14 · 9 1 4 A 9 1 4 B 9 1 4 D 9 15 · 9 1 5 A 9 1 5 B 9 16 · 9 1 6 A 9 1 6 B 9 17 · 9 1 7 B 9 1 7 C 9 1 7 D 9 2 1 9 2 2 9 2 3 9 2 4 9 2 5 9 2 6 9 3 1 Flat clamp contact clamp contact Flat clamp contact clamp contact connection clamp Flat clamp contact clamp contact Flat clamp contact clamp contact Flat clamp contact connection clamp S SMA wire S SMA wire S ΜA metal wire S ΜA metal wire S A metal wire S ΜA metal wire insulation sheet 16 (Please read the precautions on the back before filling this page). Wire-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 543060 A7 B7 V. Invention Description (

9 3 2 · 9 3 3 · 9 3 4 · 9 3 5 · 9 3 6 · 110 1 110 2 110 3 110 4 110 5 110 6 110 7 110 8 110 9 1111 · 1 1 1 1 A 1 1 1 1 B 1 1 1 1 C 1 1 1 1 D 1 1 1 4 A 1 1 1 7 A Insulation sheet Insulation sheet (Please read the precautions on the back before filling out this page) Insulation sheet Insulation sheet Insulation sheet Actuator insert pin Resistance Metal Oxide Half-Effect Transistor Transistor Resistor Resistor Flat Metal Wire Flat Plate Contacts Metal Wire X 297 mm) A7 543060 _____B7___ 5. Description of the invention (/ ^) "Shape memory alloy" or "SMA" is an alloy with thermoelastic martensite transformation, which can be deformed in the martensite phase, and the alloy Deformation will recover during the austenite phase. The SMA series suitable for the room temperature application of the present invention has an austenite-martensite transformation range, for example, a martensite end (M f) temperature of 30 to 50 degrees Celsius, which is slightly higher than the expected ambient temperature, so SM A can still maintain the martensite phase in the absence of external heating, and the austenite end (A f) temperature, such as the austenite end temperature of 80-100 degrees Celsius, needs to be low enough to meet the common engineering plastics. Compatible to minimize the amount of heat required to complete the martensitic-to-austenitic transformation (eg, electrical energy input to the SMA). Such alloys are readily available. Alloys with other transition temperature ranges can be selected for actuators designed to operate in low temperature (eg, below 0 ° C) or high temperature (eg, above 100 ° C) well-known Those skilled in the art will be able to easily select an appropriate SMA suitable for the desired purpose after considering the technology and this disclosure. It is known that when an SMA element such as a SMA wire deforms within a recoverable tension range below its Mf temperature, and then is heated to a temperature above Af, it will return to its original undeformed shape. However, re-cooling the element to temperatures below M f often does not spontaneously return to the deformed shape-shape memory effect as a one-way effect. Therefore, it is necessary to apply tension or bias to the SMA element to restore its deformed shape when re-cooled to a temperature below Mf. Although the SMA actuator of the present invention will not be discussed extensively below, it is assumed that a bias may be applied to the actuator to recover when the SMA element of the actuator cools to a temperature below M f To the deformed martensite state. The bias may be applied, for example, by a spring (as the actuator shrinks, it persists _ 18 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (please read the back first) Please note this page before filling in this page) -ni · — 1 ϋ I n a OJ · aaM MW aaaiM MM mm 雠 n. A7 543060 _B7__ 5. Description of the invention (/ “) (Please read the notes on the back before filling this page ) The bias voltage is applied continuously, and the actuator is continuously provided, in which the actuator must overcome the force of the spring to cause the actuator to move when heated; or it may be provided by a relative actuator ( Usually one actuator is heated and the other is not, but each can be heated to different degrees for precise control.) It is applied intermittently. The fixed bias is more economical, but has some actuator force. The shortcomings of the bias spring make the actuator less force that can be applied to the external load, and the spring bias also provides the maximum limit of the actuator stroke; the bias relative to the actuator provides a larger force that can be used Because when the relative actuator is not heated It takes very little time to move, and it can provide higher position sensitivity when the two provide different energy, but it is exchanged for the complexity of control and the cost of increasing power consumption. The other is to continuously provide a bias system As the actuator contracts, the force becomes constant, such as when the actuator is mounted vertically and a certain mass is suspended from the actuator to provide a bias, which allows a slightly larger actuator stroke than using a spring bias; and as Actuator contraction and reduced force. The last bias is particularly important because it allows the maximum degree of actuator contraction and also provides the fastest actuator contraction and extension when the actuator energy is supplied or not. Speed. A suitable technique for providing reduced force bias is to cause the actuator to operate a lever (such as a cam) where the lever arm increases relative to the actuator as the actuator retracts and / or the lever arm Relative to the bias decreases as the actuator shrinks. These different bias techniques are known to this technique. The SMA "metal wire" used in this application refers to the ability to shrink / stretch along the long axis It is an extended form of S MA material. Therefore, although the term "metal wire" is a typical cross-section, it is not necessarily a circular cross-section, and the 19-inch scale applies the Chinese National Standard (CNS) A4 specification (210 X 297 (Mm) A7 543060 ____B7____ 5. The description of the invention may include oval, square, rectangular or similar shapes. The "diameter" of the SMA wire with a non-circular cross section (the cross-sectional area of the wire multiplied by 4 / 7Γ) is the square root. The "stroke" of the SMM wire segment is the change in distance between the fully extended and fully contracted length of the segment. The "stroke" of the SMA actuator is the change in distance between the fully extended and fully contracted length of the actuator. If the wire or actuator includes a limited stop to limit the contraction and / or extension of the wire / actuator, the "stroke" is the distance between the limited stops, and if there is no limited stop, it may be less than the "stroke ". A "stroke multiplier" SMA actuator is a type of SMA actuator in which the stroke of the actuator in its direction of extension or contraction is greater than the extension or contraction of an SMA wire in the outer length of the actuator. A "stacked plate" SMA actuator is a SMA actuator that stacks a series of solid planar extension members ("plates") layer by layer. One end (first end) of each member is connected to the top by SMA metal wires. Non-corresponding end (second end) of the square member. Such actuators will be extensively demonstrated in this application. In a typical stacked flat plate actuator of the present invention, the flat plates are made of metal, and therefore are thermally and electrically conductive, and thus the flat plates are isolated from each other by an insulating layer in the stack. "Close proximity" means that the distance between the SMA metal wire and the heat sink should make the conduction and radiative cooling of the SMA metal wire significantly exceed (ie, at least 25%, preferably 50%) begin to be tied to the heat sink Cooling of metal wires in free air at the same temperature but without diffuser. The measurement is expressed by the diameter of the metal wire, and the appropriate interval is not more than 10 times the diameter of the metal wire. 20 paper sizes are applicable to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling (This page)

543060 A7 ____B7___ 5. Description of the Invention (| P) It is best not to exceed 8 times the diameter of the metal wire, more preferably not to exceed 5 times the diameter of the metal wire, and especially not to exceed 4 times the diameter of the metal wire. A specific minimum distance is usually required to avoid unintentional contact between the SMA metal wire and the heat sink, especially when the heat sink is conductive, such as about 50-1000 microns (relatively independent of the wire diameter), and a particularly suitable space is Between 1 and 4 times the wire diameter, for example about 3 times the wire diameter. For SMA metal wires with a diameter of 75 micrometers, it means that the proper spacing is not more than 750 micrometers, preferably not more than 600 micrometers, more preferably not more than 400 micrometers, and particularly not more than 30 micrometers. 0 microns. Particularly suitable intervals are between 1000 and 300 microns, such as 200 microns. Heat dissipation benefits have the meaning usually given, that is, a group of thermally conductive materials are placed in contact with or at least in close proximity to the object to be cooled. Suitable materials are usually metals, especially such as aluminum and its alloys, copper and its alloys (e.g. brass, bronze, and copper / zinc / nickel alloys such as "nickel silver" or "German silver") and similar metals High thermal conductivity metal. When the heat sink is conductive, it may be desirable that it should be electrically insulated from the SMA metal wire to avoid unintentional contact, and this can be done by, for example, a layer of insulating paint or the like; although (1) this may not be necessary, And (2) if the heat sink is insulating, the insulation layer should be as thin as possible to maximize the heat transferred from the SMA metal wire to the heat sink. As mentioned earlier, the heat sink may be a separate component from the actuator's solid components and SMA wires, that is, external to the actuator, in which case it may also be an active When the actuator cycle needs to cool the S MA wire, it is an active cooling element that supplies energy. One type is applicable to 21 paper sizes applicable to Chinese National Standard (CNS) A4 specifications (210 X 297 mm) --------------- (Please read the precautions on the back before filling this page).丨 Wire-A7 543060 ____ V. The active cooling element of the invention description (丨 7) is a Pe 1 tier junction element, where cooling is generated by current passing through two different metal junctions. The p e 1 t i e r junction element is well known in the art. If the active cooling element is a P e 1 t i e r junction element, the junction can be further manipulated in the opposite direction to heat to the diffuser and therefore to the SMA metal wire. Use an active cooling or heating / cooling element such as a Pe 1 tier interface element in conjunction with the circuitry and switching required by the SMA actuator (eg, energize the element to heat the radiator and / or when energy is supplied to the actuator Cooling the actuator when it is not energized) will be readily understood by those skilled in the art. However, the thermal mass of the sturdy member of the SMA actuator can be used as a heat sink by placing the metal wire close to the member; and because no external heat sink is required, this technology provides the advantages of simplified design and reduced cost , And the heat sink itself will move and reshape when the metal wire shrinks and stretches (by the movement of a solid member), so it is always optimized for the metal wire; and this will be particularly special in this application Characteristics of the discussion. "At least the middle part of the metal wire" close to the heat sink means that the length of the s μA metal wire between the solid member connection points of the SMA metal wire is at least middle 20%, preferably at least middle 40%, especially at least middle 60%, and more particularly at least the middle 7Q% is close to the heat sink. If the second characteristic of the present invention occurs, that is, when the size and position of the heat sink is such that the end portion of the metal wire connected to the solid member is not close to the heat sink, then j is at least 1 mm at the end of the metal wire, especially The end of the metal wire is not close to the heat sink 1-3 mm; the rest is close to the heat sink. Mm) (Please read the notes on the back before filling out this page)

22 A7 543060 ______B7_ 5. Description of the invention (> 〇) For long actuators, due to the conduction of the solid member under the metal wire, the metal wire near the connection point of the solid member (assuming a metal solid member) is cooled At the end of 1-2 mm, the shrinkage loss caused by this phenomenon may not be obvious; but when the actuator is to be miniaturized, the operating length of each SMA metal wire is in the order of less than 1 cm to 5 cm, especially When the distance is less than 1 cm to 3 cm, the effect of better temperature control can significantly increase the effective operating length of the SMA metal wire. For example, if the total length of the actuator wire with an operating length of 4 cm is 4.5 cm, the actuator will suffer a loss of 2 mm near the connection point of each wire, so that these parts can never heat SAf. , The effective operating length loss of the metal wire is 10%. With the second feature of the present invention, when the end loss is cut from 2 mm to 1 mm, the operating length is restored by 5%. If the actuator length is 2.5 cm and the operating wire length of the actuator is 2 cm, the loss without the second feature is 20%, and the return using the second feature of the present invention is 10%. When considering that the metal wire usually operates only within a shrinkage range of 3-4% of its operating length, it can be easily seen that as the actuator becomes shorter, for example, the temperature control improvement of the second feature of the present invention is changed. More expensive. In addition, when the actuator becomes short, because the method of maximizing the shrinkage of the SMA wire is to heat as much as A f as much as possible, increasing the demand for electrical energy input to the SMA wire to heat the end may cause excessive heating of the wire. Intermediate length, so even if not immediately, the wire will be injured after many cycles. Therefore, the combination of the first and second features of the present invention can maximize the effective operating length of the SMA metal wire, and at the same time minimize the risk of overheating the metal wire, and therefore the S MA metal wire in the actuator The best application standard is suitable for China National Standard (CAS) A4 specification (21〇χ 297 mm)-(Please read the precautions on the back before filling this page) 0. 丨 Line A7 543060 _______B7_ V. Description of the invention (Y |). As is well known in S MEMS actuator technology, the mass of the wire to be cooled per unit length is proportional to the cross-sectional area of the wire (a function of the square of the wire diameter), and the cooling rate is proportional to the surface area of the wire (As a function of diameter) is proportional. In fact, this is more complicated than the thermal conductivity of the metal wire itself, but it can be found that the cooling rate of the SMA metal wire from its Af temperature to its Mf temperature decreases substantially as the diameter of the metal wire decreases. This reduces the cycle time of the SMA actuator, because it is assumed that when sufficient energy is supplied to obtain a fast heating rate, the temperature rise time from Mf temperature to Af temperature is almost always shorter than the cooling time. For example, when a 250 micron diameter wire actuator has a cycle time of 6-7 seconds or more, a 50 micron diameter wire actuator has a cycle time of less than about 1 second, and The first cycle of a 37 micron diameter wire actuator has a cycle time of approximately 0.4 seconds. The basic design of the stroke multiplier S MA actuator includes a plurality of parallel solid (i.e., non-SMA) members that are placed centrally, which are free to slide relative to each other, each of which is connected to each other by a SMA metal wire, So that the stroke of the actuator is approximately equal to the sum of the strokes of the individual SMA wires. In a "stacked plate" actuator, the actuator comprises a set of stacked parallel plates electrically insulated from each other and connected by SMA metal wires. The construction of such an actuator is shown in FIG. Figure 2 shows a stack of flat plate actuators, which are generally represented by 20, which contains three two SMA metal wires 2 1 2 and 2 2 24. This paper standard applies to Chinese National Standard (CNS) A4 Specifications (210 X 297 mm) (Please read the notes on the back before filling this page)

A7 543060 ___B7___ 5. Description of the invention (> Μ

3 Connected solid conductive plates 2 1 to 2 3. The metal wire 2 1 2 is connected to the tablet 2 1 at the connection point 2 1 A and the tablet 2 2 'at the connection point 2 2 B and the metal wire 2 2 3 is connected to the tablet 2 2 at the connection point 2 2 A and at Connection point 2 3 B is connected to tablet 2 3. The plates 2 1 to 2 3 are formed by, for example, thermoplastics (for example, polyesters such as poly (p-styrene), polyamide resins such as nylon, polyimines such as κΑΡΤΝ®, and the like), Good low molecular polymer materials (for example, fluoropolymers such as poly (tetrafluoroethylene)) are placed between plates or a polymer material coating is applied to the plates to isolate them from each other and electrically insulate them. The plates can easily slide against each other. The flat plate 2 1 is provided with an external connection point such as a hole 2 1 1 at the end near the metal wire connection point 2 1 Α, and the flat plate 2 3 is provided with an illustration such as at the end near the metal wire connection point 2 3 B Hole 2 3 1 external connection point. When a voltage is applied to the actuator between the upper points of the plate 2 1 to 2 3, the S MA metal wires 2 1 2 and 2 2 3 are heated and contracted, thereby making the external connection points 2 1 1 and 2 3 1 Move closer together. The stroke of the actuator will be about the sum of the contraction of the metal wires 2 1 2 and 2 2 3, and therefore approximately twice the contraction of each metal wire individually, but the exerted force will not be substantially lower than that of each metal wire. Power. Obviously, the stroke of the actuator can be increased simply by increasing the number of plates and wires. In this figure where the principle of such an actuator is to be shown, 'the spacing relationship between the SMA wire and the sturdy plate is not specifically shown (or "closely,"). The variation of the actuator shown in Fig. 2 It is not shown in Fig. 3, Fig. 4, Fig. 5 A and 5 B, and the first feature of the present invention is shown here. 25 This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 g) ( Please read the precautions on the back before filling this page) Order --------- line ---- 543060 A7 _______B7__ V. Description of the invention (1) Figure 3 shows the "I-shape" used for this actuator Rod "or" dog bone "shaped plate. Plates usually shown as 30 have an extended shaft 3 1 and ends 3 2 and 3 3. External connection points 3 may be provided at either or both ends of the plate 2 A and 3 3 A, which may be, for example, holes so that external tendons or the like can be connected thereto. Although usually only one end of the uppermost plate and the other end of the lowermost plate are externally connected so that Actuator power is transferred to an external load, but it may be simpler to make all plates the same. In addition, at the end Terminals 3 2 and 3 3 are provided with metal wire connection points 3 2 B and 3 3 B. It is shown on the side of the end for simplicity, but can be connected at any convenient place. Similar metal wire connection points are also possible It is located on the other side of the end, so that two metal wires are connected between each pair of plates and the force obtained from the actuator is doubled. As can be seen from Figs. 4, 5A and 5B, The space relationship (or "close proximity") between the SMA metal wire and the sturdy plate is specifically indicated, and since the housing is shown in the following figure to support the plate to form the actuator, a slightly larger distance is expected. Series 4 shows a perspective view of an actuator, usually represented as 40, and having six stacked flat plates 4 1 to 46 and five SMA metal wires 4 1 2 to 4 56. In this figure, the shown metal wires are loose And the actuator shown is in its extended position. Plates 4 1 to 4 6 made of a conductive material, such as brass, are supported in the housing 4 7 by insulating layers (not shown), which limit the plate Move in parallel. The housing used as a SMA wire heat sink will be made of, for example, the above metal or metal The alloy is made of a suitable material for this purpose and will be electrically insulated from the plate by its inner surface such as insulating varnish or other insulating layer. Electricity can be connected at point 4 1 A (wire 4 1 2 to 26 paper sizes) Applicable to China National Standard (CNS) A4 specification (210 X 297 mm) ____________ 0 -------- Order --------- Line i Lu (Please read the precautions on the back before filling this page ) A7 543060 ___B7 _ V. Description of the invention (> jA) Plate 4 1) and Point 4 6 B (Metal wire 4 5 6 connected to plate 4 6) Apply to the actuator 'or because the plate is conductive It can be applied at any point on the plates 4 1 and 4 6, and the circuit will completely pass all six plates and five metal wires. Figures 5 A and 5 B are side views of this type of actuator, where Figure 5 A (similar to Figure 4) shows the actuator in its extended position, and Figure 5 B shows it in the retracted position with a thick arrow Shows the direction of contraction. The shrinkage shown here is symmetrical, so the ends of the plate are aligned, but this is not necessary. The stroke of the actuator will be approximately five times the individual contraction of any wire, and the force that the actuator can exert will basically not be lower than that of any wire. Although the actuator (similar to all SMA actuators of the present invention) is operated by the shrinkage of the SMA metal wire when it is heated, so that the length of the actuator is shortened as shown in Figure 5B, those skilled in the art are familiar It will be easily understood that one of the plates, such as the plate 41, can be extended, in which the extended portion 411 at the opposite end of the plate comes from the end having the connection point 41A. By comparing the relative positions of the connection point 4 6 B and the extension portion 4 1 1 in FIGS. 5 A and 5 B, it can be seen that the extension portion 4 1 1 obviously extends beyond the connection point 4 6 B when the actuator contracts. Therefore, by appropriately extending one of the outermost plates and fixing the other outermost plate, the contracting actuator can push the load instead of pulling it, as required for the desired application. In the modification of Figs. 3 to 5B, as mentioned earlier, the SMA wire shown is only on one side of the tip, but may have a second set of wires on the other side of the tip to double the actuation force. In addition, as previously mentioned, the number of plates and wires can be increased as needed to further increase the stroke of the actuator. 27 This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page) Order · · 543060 A7 __B7__ V. Description of the invention (/) The feature of minimizing the total voltage required to drive a multi-plate actuator when increasing is the use of an odd-numbered plate (even-numbered SMA metal wire), and the actuator without applying a voltage to the outermost plate (assuming the plate resistance is significantly lower than In the case of metal wire resistance, the resistance of the actuator is the sum of the resistances of all metal wires), and the outermost plate is electrically connected and a voltage is applied between the two outermost plates and the middle plate (the resistance of the actuator is only Is a quarter of the total resistance of all metal wires). This can use a lower supply voltage for a given current through the actuator. If the outermost plate is not electrically connected and a voltage is applied between an outermost plate and the middle plate, only half of the energy can be supplied to the actuator. Of course, it is also possible to design a power supply circuit for the actuator so that each SMA metal wire can independently supply energy, or to supply energy to any number of selected metal wires (for example, one-third of the metal Line instead of one-half as in the previous paragraph), and such changes are included in the present invention. The casing 47 is placed around the flat plate as a heat sink for the metal wires so that the metal wires are "closely" (as defined above) to the casing. Fig. 6 is a top view of a solid member ("flat plate") used in the SMA actuator of the present invention, showing the space relationship between the SMA wire and the solid member, which is used as a heat sink. For the sake of simplicity and conciseness, in FIG. 6 to FIG. 8B, only the characteristics of the solid members related to the metal wire interval are shown (for example, the characteristics of the power supply to the actuator and the movement of one plate to another plate, etc.) (A part of it is shown in FIGS. 3 to 5B). Also for simplicity and ease of explanation, the SMA wire 61 shown is attached to the same solid member at the ends 6 2 A and 6 2 B, and this is shown in Figures 7 to 28 (Please read the precautions on the back before filling this page ) · 'This paper size is in accordance with China National Standard (CNS) A4 (210 X 297 mm) A7 543060 ___ B7______ V. Description of Invention (vL) (Please read the precautions on the back before filling this page) Figure 8B Shown in a similar manner; of course, in an actual actuator, each metal wire is connected between two adjacent solid members to move them relative to each other (as shown in Figs. 4 to 5B and Fig. 9) ° The distance "d" between the SMA metal wire 6 1 and the solid member 62 is such that the SMA metal wire is "closely" (as defined) closest to the straight edge 6 3 of the solid member of the metal wire; in actual actuation In the device, the SMA wire will be "closely" to the closest edge between the solid members to which it is connected. In this way, the temperature of the metal wire is controlled by the heat dissipation effect of the solid member; and the overheating deviation of the middle part of the metal wire and the increase in the cooling rate of the metal wire when no power is applied can be avoided to achieve the first cost of the invention Advantages of features. It provides advantages in cycle time and is due to the minimization of overheating (depending on the control method used to heat the wire-if the heating is controlled only according to the contraction shape curve, the advantage is less obvious, but if the control is based on The metal wire temperature sensing method has obvious advantages) and provides the advantage of working life. Since the SMA metal wire 6 1 is connected to the ends 6 2 A and 6 2 B of the solid member 6 2 in an electrically conductive manner (for example, by clamping), not only does the SMA metal wire conduct through the air to the solid member 6 2 straightly. The heat loss at the edge 63 is also the heat loss that is conducted directly from the end of the wire to the ends 6 2 A and 6 2 B of the solid member 62 and also from the air to the ends 6 2 A and 6 2 B. Therefore, when power is applied to the metal wire, there will be a temperature gradient along the metal wire that is colder at the end of the metal wire than at the middle. The "operating length" caused by the SMA metal wire that cannot heat the end part of the metal wire to A f and does not overheat the middle part of the metal wire (when the actuator supplies energy and does not hurt the metal wire, it can fully shrink Loss of metal wire length) 29 This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) 543060 A7 _____B7 _ V. Description of the invention (/)) Loss of about 2 mm at each end, of course Depending on the thermal mass of the solid member 6 2 and in particular on the ends 6 2 A and 6 2 B to which the metal wire 6 1 is connected. Fig. 7 is a top view of a solid member ("plate") for the SMA actuator of the present invention, which shows the space relationship between the SMA metal wire and the solid member, wherein the solid member is used as a heat sink and shows the present invention. The second characteristic. The distance “d” between the S MA metal wire 71 and the solid member 7 2 is such that the metal wire is “closely” (as defined) opposite the middle part of the metal wire and closest to the straight edge 7 of the solid member of the metal wire. 3. For example, the distance between the metal wire of 75 micrometers and the closest edge of the solid member is between 150 micrometers and 300 micrometers. In this way, the temperature of the metal wire is controlled by the heat dissipation effect of the solid member, and the overheating deviation of the middle part of the metal wire and the increase of the cooling rate of the metal wire can be avoided, thereby achieving the advantage of the first feature of the invention. Since the recess 7 4 cuts into a solid member at each end of the edge 7 3, the heat transfer from the wire to the flat plate through the air at the end will be reduced, and it will reduce the end loss of the operating length of FIG. 6 described above. The depth "t" of each recess 74 will cause the metal wire to not "closely" to the solid member at the bottom edge 75 of the recess, for example, so that the metal wire is at least 10 from the bottom edge of each recess Double the diameter of the metal wire and specifically at least 15 times the diameter of the metal wire (for example, for a 75-micron metal wire, at least 750 micrometers and especially at least 1,000 micrometers) to reduce the rugged components as a heat sink Cooling effect, and the width "w" of each recess will reduce the above-mentioned end cooling effect to a practical level. A suitable width "w" will be at least 1 mm and up to about 3 mm, but for rectangular recesses 7 4 are usually 1 to 2 mm. 30 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page)

A7 543060 ___B7__ V. Description of the invention M) Figure 8 A is a top view of another solid component ("flat plate") of the SMA actuator of the present invention, which shows the space relationship between the SMA metal wire and the solid component. The solid member acts as a heat sink and shows a second feature of the present invention. The distance “d” between the S MA metal wire 81 and the solid member 8 2 is such that the metal wire is “closely” (as defined) opposite the middle portion of the metal wire and closest to the straight edge 8 of the solid member of the metal wire. 3. In this way, the temperature of the metal wire is controlled by the heat dissipation effect of the sturdy member; and the overheating deviation of the middle part of the metal wire and the increase of the cooling rate of the metal wire can be avoided, thereby achieving the advantage of the first feature of the invention. Since the recesses 8 4 are cut into solid members at each end of the straight edge 8 3, the heat transfer from the wire to the plate at the end will be reduced, and it will reduce the end loss of the operating length of FIG. 6 described above. The depth "t" of each recess 8 4 will cause the metal wire not to be "closely" to the solid member at least at the bottom edge 85 of the recess, for example, so that the metal wire is at least 7 from the bottom edge of each recess 50 microns and especially at least 1,000 microns to reduce the cooling effect of the solid component as a heat sink, and the width "w" at the top of each cavity will reduce the above-mentioned end cooling effect to a practical level. A suitable width "w" will be at least 2 mm and up to about 4 mm, but the top of each trapezoidal recess 8 4 is usually 3 mm, and the width at the bottom of each recess is usually the rectangular recess of Fig. 7 The lower limit of the width of the hole 74 is, for example, 1 to 2 mm, particularly 1 to 1.5 mm. For S M A metal wires with larger or smaller diameters and strong members with larger or smaller thickness or thermal conductivity, the depth of the recesses of the strong members will be enlarged or reduced, because the metal wires pass through the air to the Cooling will change with the change of metal wires and solid components. 31 t paper size applies Chinese National Standard (CNS) A4 specifications (210 X 297 Public Love 1-(Please read the precautions on the back before filling this page)

A7 543060 ___B7_____ V. Description of the invention); but the width change is relatively small, because it is only partly determined by the direct heat conduction between the S MA metal wire at the connection point and the solid member. FIG. 8B is a top view of another sturdy member (“flat plate”) used in the S MA actuator of the present invention, which is similar to the sturdy member of FIG. 8A, in which the SMA wire 8 1 1 is “closely adjacent” (eg Definition) Opposite the middle part of the metal wire is the edge 8 1 3 of the solid member 812 closest to the metal wire, but it shows a circular recess 8 1 4 instead of the sharp-angled recess 8 4 in FIG. 8 And the size and thermal characteristics of sturdy components, and assuming specific operating parameters such as ambient temperature and desired operating temperature of the metal wire, the distance "d" can be designed in the following manner, with a depth "t" and a width "w" Shape and structure. (1) Calculate the cooling of the metal wire and the metal wire at the connection (clamping) between the solid members; (2) Calculate the metal wire through air to the solid member containing both the end of the solid member and the edge closest to the metal wire Cooling for the selected starting solid member shape (for example, the shape of FIG. 7); (3) from these parameters, determine the temperature profile for the metal wire; (4) iteratively modify the shape of the solid member and determine For the temperature curve of the metal wire, the goal is to minimize the temperature difference along the metal wire by changing the shape of the solid member. When considering the technology of those who are familiar with S MA actuators and engineering, and the information that can be obtained including the documents referenced in this application and this disclosure, it will be easily completed by those who are familiar with S MA actuators and engineering. At 32---------------This paper size applies Chinese National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page)

543060 A7 B7 V. Description of the invention) Design of the proper shape of the sturdy member of the S MEMS actuator of the present invention ° (Please read the precautions on the back before filling this page) When the heat sink is not around the actuator plate When the housing or the plate of the actuator itself is completely outside the actuator, what is needed for the first concept of the present invention is that the heat sink should be "closely" to the SMA metal wire of the actuator, and it is believed that The design does not need an example, it will be self-explanatory from the description. If necessary, a considerable degree of freedom can be obtained in designing the heat sink to increase its efficiency, for example, by adding cooling fins or other heat dissipation features to the side of the heat sink without facing the actuator wires; however Using a completely external heat sink will increase the complexity and size of the completed actuator. An advantage of an external heat sink is that it allows the use of a heat sink with an active cooling effect such as a Pe 1 t i e r junction element, which can provide a sub-ambient temperature environment to the SMA wire during a cooling cycle. The control of the Pe 1 tier interface element can be matched with the control of the SMA actuator, so when the power is removed from the SMA wire, the power is applied to the Pe 1 tier junction element to cool the SMA wire. Minimize time. If the cooling element is a Pe 1 tier interface element, it is more likely to operate the interface in the reverse direction when supplying energy to the actuator to add heat to the heat sink and thus heat to the SMA metal wire to wire the metal wire. The heat loss is minimized and the cycle speed of the actuator is increased. Example-Miniature Stroke Multiplying Actuator Fig. 9 is an exploded view showing the flat plate and wire assembly of this embodiment generally designated 9 1 and the base 92 on which the flat plate is assembled. These plates will be stacked in a parallel array on the base, with the plate 9 1 1 as the lowest, followed by the plates 9 1 2 to 9 1 6 and the upper plate 9 1 7 33 This paper size applies to the Chinese National Standard (CNS ) A4 specification (210 X 297 mm) A7 543060 _____B7_ 5. Description of the invention (1 I). Each plate is made of a strong but flexible material 'to allow the material on the SMA wires 9 2 1 to 9 2 6 to be clamped at the clamp points 911A and 912B to 916A and 917B, respectively, without harming (Excessive compression of SMA wire leads to breakage and transformation characteristics) Metal wire. Suitable materials for the plate are semi-rigid box-type brass' or semi-rigid "nickel silver" alloys. Other metal wire connection methods can be used 'but the clamp is an attractive method that is simple, economical and does not increase the size of the assembled actuator. The lowermost plate 911 of the actuator plate having the maximum stroke relative to the uppermost plate 917 is provided with a connection point 9 1 1 C for external connection to a load pulled when the actuator is contracted, and for power leads (not shown ) The connection clip 9 1 1 D. The middle plate 9 1 4 is also provided with a connection clip 9 1 4 D for connection of a power lead (not shown). The uppermost flat plate 917 is provided with, for example, a connection point 9 1 7 C for connecting an actuator to an external structure, and also a connection clip 9 1 7 D for connection of a power lead (not shown). The base 92 may be made of any suitable non-conductive or insulating material such as thermoplastic for engineering thermoplastics, and includes a base plate 9 2 A protruding from two spaced-apart pins 9 2 B and 9 2 C. Each plate 9 11 to 9 16 is provided with a slit (unnumbered) 'and the uppermost plate 9 1 7 is provided with two holes (unnumbered), and the plates are placed in the order of 9 1 1 to 9 1 7 On the base plate 9 2 A, there is an insulating layer between each pair of plates (which may be, for example, a piece of polymer sheet separated by an insulating material or an insulating layer that may be coated on one or both sides of the plate) So that the pins 9 2 B and 9 2 C pass through the slits of the plate 9 1 1 to 9 1 6 and the holes of the plate 9 1 7. The plate shown in the figure is at the clamp connection point 9 1 1 A to 9 34 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page) • Line · 543060 A7 _____B7_ V. Description of the invention 1 7 There is a recess (unnumbered) of a flat plate as shown in Figure 7 or Figure 8 near the B and the metal wires 9 2 1 to 9 2 6 are separated from the edge of the corresponding flat plate, so that They are "closely" to these edges, as described in Figs. 6 to 8; therefore, for the actuators shown in Figs. 9 and 10, the first and second features of the present invention can be obtained. The plate is supported on the plunger, so it lies horizontally on the base plate by any conventional method; and a particularly convenient method is a well-known method for assembling plastic parts, such as VELOM Demonstrated by the ND® joining system, the heat deformation ("standard stake") protrudes from the ends of the pins 9 2 B, 9 2 C above the plate 9 1 7 (as shown in Fig. 10), so that it blocks the plate. Fig. 10 is a side view showing the assembled actuator. For the sake of clarity, although each plate 911 to 917 and the pinch points 911A to 9 1 7 B are shown, the SMA metal wire is not shown. Plates 9 1 1 to 9 1 7 are made of semi-rigid nickel silver with a thickness of 200 microns [a kind containing 5 5.2 5% of copper, 27.17% of zinc, 17.22% of nickel, 0.26% of fierce, and 0.2% Alloy of lead; alloy 770 of ABC Metal Co., Ltd., Elmhurst County, Illinois, USA], to allow proper clamping of non-harmful SMA wire and still provide sufficient hardness of the plate. A thin sheet of PET [D up ο nt Teijin MYLAR® A] with a thickness of 250 micrometers is placed between the plates 9 3 1 to 9 3 6 to electrically insulate the plates from each other and allow the plates 9 1 1 to 9 16 Sliding with low friction as the actuator contracts and extends. The metal wire is a 7 5 micron Dyna 1 1 oy FLEX I NO LTM titanium-nickel alloy with a transition temperature of 90 degrees Celsius, and it is loaded with 10 grams of 35. This paper size applies to China National Standard (CNS) A4 specifications (210 X 297 mm) ----------------- (Please read the precautions on the back before filling this page) Order: Line A7 543060 _ B7_ V. Description of the invention () Today) The following preload tensions are used to avoid slack that may cause the actuator to lose its movement. The distance between the clamps (the length of each metal wire segment) is 27 mm: and the plate has a recess at each clamp point 'the shape is similar to the shape of Fig. 8B, which has a depth of 1.0 mm' The width at the bottom of the cavity of about 1.2 mm and the width at the top of the cavity of about 3.0 mm. When the actuator is assembled, the wire is clamped to the plate so that it is about 200 microns from the nearest plate edge. Suitable materials for the base are, for example, engineering thermoplastics, polycarbonates, or the like filled with nylon 6/6 (NY LATRON® GS). The final actuator has a height of 6.1 millimeters, a width of 5.3 millimeters, and an extended length of 3 8.6 millimeters (from the connection point at the end of the lowermost plate to the connection clip for the power lead at the opposite end of the uppermost plate Point] and a contraction length of 3 4.6 mm, with a stroke of 4 mm (12% stroke / length ratio). The weight of the complete actuator is only 1.1 grams. The actuator has a contraction force of 70 grams, a restoring force of 4 grams, and a limiting force of more than 400 grams. At 4.0 volts, the peak current is 470 mA. The plungers 9 2 Β and 9 2 C interact with the internal slits of the plate as a mechanical stop, which limits the maximum extension and contraction of the actuator and the stroke of the plate, especially for the plate 91 which may be connected to the load. In this way: (1) the excessively extra-stretching force exerted by the actuator's acting force will not over-pressurize the SMA element; and (2) the actuator will not shrink to its performance limit, thereby ensuring that even in As the S MA element is well known, when the S MA element ages and loses its ability to recover, the actuator will still be able to move within the full range between restricted stops. In another feature of the present invention, the actuator can be provided with an electronic sensor. 36_ This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling in (This page) -------- Order --------- line — 543060 A7 _-_____B7 _ 5. Description of the invention Cjf) To detect the maximum extension or contraction of the actuator, for example, and In other words, the sensor that detects the maximum contraction of the actuator can be connected to a circuit switch that supplies power to the SMA wire. This open relationship allows power to flow to actuation when the actuator is operating within its normal contraction range. Device, but cut off power when the actuator reaches maximum contraction. An example circuit that provides this function is shown in Figure 11 especially for digital control of actuators. In Fig. 11, the actuator is shown schematically at 1101. The actuators 1 1 0 1 are the seven plate actuator types shown in FIG. 9 and FIG. 10, and the lowermost plate 1 1 1 1 is the plate having the largest range of movement (that is, to be connected To the load plate), and the remaining plates are not shown. By connecting the metal wire 1 1 1 1 A to the lowermost plate 1 1 1 1 and the metal wire 1 1 1 7 A to the uppermost plate, the lowermost plate 1111 and the uppermost plate are connected to The figure shows a + V power supply, and the power is supplied to the actuator 1 1 〇1; and the middle (fourth) plate is grounded through the drain of M OSFET 110 5 through the metal wire 1 1 1 4 A. Therefore, in this circuit, two "half" actuators are operated in parallel at a low voltage, rather than applying a higher voltage between the uppermost and lowermost plates, as previously described. The conductive plate 1 1 1 1 is electrically including a circuit from the contact 1 1 1 1 C through the plate (shown as 1 1 1 1 B in the circuit) to the contact 1 1 1 1 D. When the actuator 1 1 0 1 is fully extended, that is, 0% contraction, the contact 1 1 1 1 D touches the plug 1102, and the 0% signal is at + V (digital high state), which allows external Control circuit (not shown) senses 0% position; similarly, 37 paper sizes are applicable to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page)

A7 543060 _____ Β7 ____ V. Description of the invention (flying) When the actuator 1 1 0 1 is fully retracted, that is, 100% contraction, the contact 1 1 1 1 C hits the plunger 1 1 〇3, and 1 0 The 0% signal is at + V (digital high state), which allows the 100% position to be sensed by an external control circuit (not shown). When the CTRL signal is applied, it raises the gate voltage of MOSF ET 1 1 0 5 to make MOSF 1 D 1 0 5 conductive and to apply power to the panel 1 1 1 1/1 1 1 7 and the panel 1 1 1 4 actuator, thereby supplying energy to the actuator 1 1 0 1 and shrinking the SMAA wire and the actuator 1101 itself. When it starts to shrink, the contact 1 1 1 1 D will disengage from the pin 1 1 02, and the 0% signal will become a digital low state. When the actuator 1 1 0 1 is fully retracted, the contact 1 1 1 1 C will touch the plunger 1 1 0 3, and the 100% signal will become a digital high state; similarly, the transistor 1 1 0 6 will be turned on, thereby reducing the gate voltage of MOSFET 1 1 0 5 and causing it to shut down the power supply to the actuator 1 1 0 1. When the actuator is cooled and extended again, the contact 1 1 1 1 C is disengaged from the plunger 1103, MoSFE τ 1 1 0 5 is turned on again, and the actuator is contracted again. Therefore, as long as the C T R L signal is applied, the actuator will contract to a 100% contraction and then circulate very close to 100% contraction. Resistors 1 1 0 4 and 1 10 7 to 1 1 0 9 control the current flowing through the circuit. For the actuators shown in Figs. 9 and 10 and described in the above description, the cycle rate for the contraction and re-extension of this approximately 100% contraction is approximately 50 Hz, so that when the consumed power self Actuator 1 1 0 1 appears to maintain full contraction during adjustment. For this type of actuator, the appropriate MOSFET is I RLM L 2 5 0 2 and the appropriate transistor system MMB T 3 9 0 4 and appropriate 38 This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) (Please read the precautions on the back before filling out this page) Order --------- Line ---- A7 543060 5. The resistance of the invention description (TjL) is 1 0 κ Ω. These components and plugs 1 102 and 1 103 can be surface mounted on soft circuits located below the base of the actuator and inside the hollow portion, thereby minimizing the size of the actuator and control circuit. The advantages of using a circuit such as that shown in Figure 11 are twofold. First, when the actuator is retracted to its desired level, the circuit immediately cuts off the power supplied to the actuator. This ensures that whether or not a control signal is applied, once the actuator reaches the desired contraction limit, the actuator no longer consumes power, except when the actuator forces itself to stop or attempt to contract further. Minimize power consumption. This also ensures that even when the desired shrinkage is reached, the S MA wire of the actuator will not be overheated by continuously applied electrical energy, and the reduction in tension and maximum temperature of the S MA wire reduces the metal fatigue of the actuator and Maximize the operating life (cycles) of the actuator. Second, the circuit can maintain the actuator at the desired degree of contraction that may extend the cycle at the lowest power consumption and the lowest SMA wire temperature. Whenever a control signal is applied and the actuator is not fully retracted, electrical energy is applied to the actuator to contract it. Once the actuator is fully retracted, the power is cut off. However, once the SMA wire is cooled and re-extended, the actuator re-expands and re-establishes power to the actuator. Then, the actuator is contracted again, the power to the actuator is cut off again, and so on. The switching cycle can be fast enough so that the SMA metal wire basically reaches a fixed temperature that happens to be sufficient to maintain the actuator at its maximum contraction, for example, which may be below A 0 degree, which again minimizes the metal fatigue of the actuator and the working life maximize. In addition, because the SMA metal wire only reaches the temperature required to reach the maximum shrinkage, once the control signal is cut off, it will be cooled faster than if it had been heated to A "Si_ 39 This paper size applies Chinese National Standards (CNS) A4 specification (210 X 297 mm) (Please read the precautions on the back before filling this page) .0 ·-line · 543060 A7 ______B7___ pr 5. Description of the invention Λ), and this will reduce the cycle time of the actuator (Increase the cycle rate.) Although the temperature control advantages of this concept are explained in detail only in terms of empirical operation of the SMA actuator, those skilled in the art will clearly understand that this embodiment can be applied to the need or want to implement from this Examples of all S MEMS actuators, such as those where the desired contraction is limited to less than the maximum contraction of the actuator, or the actuator wants to maintain its action (contraction) for an extended period of time, or Actuators want faster cycling and / or longer life; and methods other than those shown can be used to achieve sensing and switching. For example, this control technology can be used remotely but effectively Ground connection Implemented with sensors / switches to the actuator (eg, connected to an actuator-connected load); and can be achieved by a purely electronic circuit and a simple switch with maximum contraction near the actuator rather than by referring to Figure 1 The transistor circuit described in 1 is implemented. Therefore, the fourth concept of the present invention can be easily applied to the SM of the present invention having only the first concept, the first and second concepts, or all the concepts of the present invention. Actuator When considering the technology and information available to those who are familiar with S MEMS actuators and cooperating electronic devices and their applications, it includes reference to this application and the documents disclosed therein. For actuators, the technician will be able to easily implement the software required for various functions including sensing and control functions. Although several concepts of the present invention have been shown to provide their respective advantages when applied to SMA actuators , So that an SMA actuator characterized by only one of the ideas will show advantages over an actuator that does not use that idea, it is clear that if more than one idea is applied to a given actuator, ( _____ 40 ^ The scale applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) > '" First (Please read the precautions on the back before filling this page) Fistula-line A7 543060 ___ B7___ 5. Application of the invention description The advantages of the concept are additive, so using more than one S MA actuator of the present invention can show greater advantages than using fewer concept actuators. Those skilled in the art will understand that without departing from this The scope and spirit of the invention are various modifications and changes of the invention. Although the invention has been described in conjunction with a specific preferred embodiment, it should be understood that the scope of the invention should not be unduly limited to that specific embodiment. In fact, Various modifications used to implement the above-mentioned mode of the present invention are intended to be included in the scope of this disclosure and patent application. (Please read the notes on the back before filling this page.) Standard (CNS) A4 specification (210 X 297 mm)

Claims (1)

543060 C8 D8 6. Scope of patent application (please read the notes on the back before writing this page) 1 · A Stroke Multiplier Shape Memory Alloy (SMA) Actuator, which contains at least three solid parallel extension members, each of which The system has a long axis and the systems can slide relative to each other parallel to the long axis. Each of them is connected to each other by an S MA wire, so that the stroke of the actuator is substantially equal to the stroke of the S MA wire. In a sum, at least one middle portion of the S MA metal wire is close to a heat sink. 2 · The actuator according to item 1 of the patent application scope, wherein the extension member is a parallel flat plate. 3. The actuator according to item 2 of the patent application, wherein the extension member is a stack of parallel conductive plates electrically insulated from each other. 4. The actuator according to item 3 of the patent application, wherein every two of the plates are separated by a layer of polymer material. 5. The actuator according to item 4 of the patent application, wherein the flat plate includes an upper flat plate, a lower flat plate, and at least one middle flat plate, and each flat plate has a first and a second all the first flat plates. The ends are generally aligned higher than one ground and the second end of the plate is substantially aligned higher than one ground. The two metal wires have a jW4l connected to an end near the first end of the lower plate and Connected to the second end and the second end of the intermediate plate immediately above it, a second SMA wire has a first end near the first end of an intermediate plate immediately below a square plate and a connection A second end near the second end of the upper plate, and, if there is more than one intermediate plate, an SMA metal wire has a first end near the first end of each intermediate plate and a immediately adjacent to it The paper attached to the second end of the middle plate above is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 543060 A8 B8 C8 D8 6. The second end near the scope of patent application. 6. The actuator according to item 1 of the scope of patent application, wherein the distance between the middle portion of each SMA metal wire and the heat sink is not more than 10 times the diameter of the metal wire. 7. The actuator according to item 6 of the patent application scope, wherein the distance between the middle portion of each SMA metal wire and the heat sink is not more than 8 times the diameter of the metal wire. 8. The actuator of claim 7 in the scope of patent application, wherein the distance between the middle portion of each SMA metal wire and the heat sink is between 1 and 4 times the diameter of the wire. 9. The actuator according to item 1 of the patent application scope, wherein at least 20% of the middle of each SMA metal wire is close to the heat sink. 10. The actuator according to item 9 of the scope of patent application, wherein at least 40% of the middle of each SMA metal wire is close to the heat sink. 1 1. The actuator according to item 10 of the scope of patent application, wherein at least 70% of the middle of each SMA metal wire is close to the heat sink 0 1 2. The cause due to item 1 of the scope of patent application The actuator, wherein at least 1 mm of the end of each end of each SMA metal wire is not close to the heat sink. 13. The actuator according to item 11 of the scope of patent application, wherein at least 1.5 mm of the end of each end of each SMA metal wire is not close to the heat sink. 1 4. If the actuator of the scope of patent application No. 1 of which, the paper size of this paper is applicable to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before writing This page), * i-rtr 11 line 543060 A8 B8 C8 D8 VI. Patent application scope Heater is a solid component containing the actuator. 15 · The actuator according to item 4 of the patent application, wherein the heat sink comprises a parallel conductive flat plate of the actuator. 16 · The actuator according to item 15 of the scope of patent application, wherein each plate has an edge parallel to the long axis and closest to one of the S M A metal wires connected to the plate near an end of the plate. The edge is such that at least 60% of the middle of each metal wire is close to the edge, and a recess is formed near the connection point of the metal wire to the plate, so that the metal wire is at least away from The first 1 mm of the connection point of the plate is not close to the edge. 1 7 · The actuator according to item 1 of the patent application scope, wherein the radiator is external to the actuator. 18 · The actuator according to item 17 of the patent application, wherein the radiator is an active cooling element. 19 · If the actuator of the scope of application for patent No. 1 has a desired contraction limit and a power supply circuit for supplying power to the actuator to cause it to contract, the power supply circuit includes a switch, It is usually closed when the actuator is contracted to less than the desired contraction limit and is opened by the actuator when the desired contraction limit is reached. 2 0 · An SMA actuator having a desired contraction limit and a power supply circuit for supplying power to the actuator to cause it to contract, the power supply circuit includes a switch which is activated during the actuation When the device shrinks to less than the desired contraction limit, it is usually closed and when the desired contraction limit is reached, it is opened by the actuator. 3 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) — '" (Please read the precautions on the back before writing this page)